The present invention relates to Wortmannin analogs, and has application to methods of using these derivatives to inhibit PI-3-kinase activity and to treat certain malignant tumors. Wortmannin is a known potent inhibitor of phosphotidylinositol-3-kinase (PI-3-kinase) and anti-cancer agent. Wortmannin is a naturally occurring compound isolated from culture broths of the fungus Penicillium wortmannin and has the basic structure shown in U.S. Pat. No. 5,480,906, which is incorporated herein by reference.
One of the disadvantages of wortmannin is its toxicity to living creatures. Even in low dosages, wortmannin in pure form was often lethal to laboratory animals.